This research project is designed to examine pathogenic mechanisms in gonococcal infections. Most of the studies will employ an experimental model of human fallopian tube pieces in organ culture for quantitation of the rate of damage to human genital mucosa by gonococci. This model, developed by the Principal Investigator and colleagues, will be used to test the virulence of gonococcal strains that differ in certain characteristics to determine the relation of those characteristics to virulence. A toxic factor elaborated by gonococci will be sought and efforts to isolate and purify such a factor of factors will be made. Studies will also be directed at determining the mechanisms by which gonococci attach to and invade human genital mucosal cells. Techniques for detecting small amounts of capsular material will be developed and applied in a search for gonococcal capsules. The possible formation of L-phase variants by gonococci and their persistence in the fallopian tube mucosa will also be studied. It is hoped that a better understanding of the mechanisms whereby gonococci cause disease will lead to better means of blocking these mechanisms and thus more effective prevention of gonococcal infections.